This invention relates to a retainer for the coil assembly of a solenoid valve. More specifically, this invention relates to such a retainer which permits the solenoid actuator assembly, of a solenoid operated valve, such as may be conventionally used in refrigeration systems or the like, to readily be removed from the valve body so as to facilitate repair of the valve.
In many instances, solenoid valves are commonly used to regulate or control the flow of fluid, such as a refrigerant in a refrigeration system, or to control the flow of steam in a heating system. Additionally, there are many other applications for solenoid operated valves in many industrial applications. Typically, these valves include a valve housing or body having a flow passage therethrough with a valve seat within the flow passage. A valve member is movable between a closed position in which it sealingly cooperates with the valve seat so as to block the flow of fluid through the passage and an open position so as to permit the flow of fluid A solenoid actuator is provided which typically comprises a coil of wire so wound as to generate a magnetic flux field through its center when energized. A movable armature is connected to the valve member so that upon energization and de-energization of the coil, the magnetic flux generated thereby serves to move the armature axially into and out of the center of the coil so as to result in opening and closing movement of the valve.
In many types of solenoid valves, such as is shown in U.S. Pat. Nos. 2,343,806, 3,281,740 and 3,262,027, the movable armature for the solenoid valve is movable axially within a so-called enclosure tube which is sealably secured relative to the valve housing. Typically, the enclosure tube is of a relatively thin gauge non-magnetic sheet metal, such as stainless steel or the like, and has an open inner end so that the armature may be readily connected to the valve member and a closed upper end. The enclosure tube is sealed relative to the valve housing such that the escape of the fluid (e.g., refrigerant) is prevented.
Further, a solenoid coil is typically wound on a spool and the spool and the coil surround the outer surface of the enclosure tube such that the lines of flux of the coil run generally axially through the enclosure tube and through the core member. Solenoid valves may be either of normally open or of normally closed construction, depending upon their particular application, and solenoid valves typically rely on a spring to move the valve to a desired position (either to its open or closed position) when the valve is in its de-energized position. Further, the valve typically includes a housing which surrounds and encloses the solenoid coil
As shown in U.S. Pat. No. 2,343,806, the housing was secured relative to the enclosing tube by means of a screw or the like. In U.S. Pat. No. 3,262,027, the outer, closed end of the enclosure tube is shown to extend through an opening in the outer face of the housing for the solenoid, and the solenoid housing together with the solenoid therewithin is secured relative to the enclosure tube by means of a snap ring received in a circumferential groove formed in the outer end of the enclosing tube. Still further, in U.S. Pat. No. 3,281,740, a hinged plastic securement member is affixed to the outer end of the enclosure tube extending out beyond the outer face of the enclosure and a cap is adapted to snap into place to a collar portion of the plastic retainer thereby to positively hold the solenoid assembly in fixed axial position on the enclosure tube.
However, it has been found in practice that the various prior art threaded fasteners, snap rings, and plastic snap closures and other snap caps for holding the solenoid on the enclosure tube were difficult to remove and install by service personnel in the field and were easily lost. It will be appreciated that it is a generally common procedure for field service personnel, in servicing refrigeration systems, to remove the solenoid actuator from the solenoid valve for testing or replacement without opening the refrigeration system merely by removing the solenoid coil from the valve and by replacing it with another.
Thus, there has been a longstanding need so as to permit field service personnel to readily remove the solenoid actuator of a solenoid valve from the valve assembly per se and to permit the ready reinstallation of the solenoid actuator. It has been further desirable that this could be accomplished without the use of even simple handtools.